add explanatory comments

- fixes #61 (comment)
- fixes #61 (review)

Author: casperdcl

Diff for: .circleci/config.yml

@@ -32,6 +32,8 @@ jobs:
       - install
       - run: mkdocs build
       - add_ssh_keys:
+          # tell CI to use openworm-bot@github's ssh key (for deploy permissions)
+          # https://circleci.com/docs/2.0/add-ssh-key/
           fingerprints:
             - "ad:f1:51:b7:68:cb:19:08:b2:7d:63:e3:eb:79:1a:63"
       - deploy:
@@ -49,12 +51,11 @@ workflows:
       - mkdocs:
           filters:
             branches:
-              ignore: /^gh-pages/
+              ignore: /^gh-pages/  # no tests exist on deployed pages branch
   poll:
     triggers:
       - schedule:
-          # every hour
-          cron: "0 * * * *"
+          cron: "0 * * * *"  # every hour
           filters:
             branches:
               only: